1. Field of the Invention
The present invention relates to a printed circuit board terminal, made of a metal wire rod, which is inserted into a through hole in a printed circuit board and is soldered to an electrically-conducting path, and to a connector having the printed circuit board terminal.
2. Description of Related Art
Conventionally, a printed circuit board having many relays, fuses, and the like, to distribute electric power to various electric components, is used as an electric junction box mounted on a vehicle. In such a printed circuit board, a printed circuit board terminal is used to electrically connect an electrically-conducting path on the printed circuit board to an external electrically-conducting path. Generally, a tip of the printed circuit board terminal is inserted into a through hole in the printed circuit board, and is soldered to the electrically-conducting path on the printed circuit board, and thus is fixed to the printed circuit board.
In recent years, a density increase in implementation and wiring of a printed circuit board is desired. In order to respond to such a density increase, it is considered to make the pitch of the printed circuit board terminals narrow. However, when the pitch of the printed circuit board terminals is narrowed, the interval between the through holes provided in the printed circuit board also becomes narrow, and formation of the through holes and soldering become difficult. Further, it is difficult to secure the strength of the printed circuit board between the through holes.
Accordingly, Japanese Patent Application Publication No. 2000-30834 discloses a printed circuit board terminal in which only a tip portion, which is inserted into a through hole, is processed to have a small width dimension, such as by cutting. According to such a printed circuit board terminal, while a sufficient width dimension of the member is secured at the connection side end portion, the diameter of the through hole provided in the printed circuit board can be reduced.
However, when a metal wire rod is used as the printed circuit board terminal, since both of the opposite side surfaces in the width direction of the terminal are processed, such as by cutting, to make the width of an insertion portion of the printed circuit board terminal narrow, a non-plated base material is exposed at both side surfaces of the terminal. Therefore, a solder wick may become poor. In particular, in recent years, lead-free soldering is more likely to be used, in consideration of impacts on the environment. In the lead-free soldering, the reduction in solder wettability occurs more prominently due to peeling of plate.
Japanese Patent Application Publication No. 2000-30834 discloses that, in order to improve solder wettability, the printed circuit board terminal made of metal wire rod is used, and after the terminal insertion portion is processed to reduce the width, such as by cutting, a conductive metal plated layer is provided on the surface. However, the after-plating process makes the manufacturing process of the printed circuit board terminal complicated, and increases the cost. Accordingly, another solution is desired.